Corrosion protection of such connectors and protection of the electrical lines in the connectors is often required when they are employed in wet environments, for example in humid conditions or in underwater applications. Such forms of connector are often provided with seals, for example in the form of "O" rings, against moisture ingress, but such seals often do not function effectively due to the tolerances in the parts and/or mechanical loading of the connectors, and additional sealing of the connector is necessary. We have found, however, that the use of adhesives or mastics in the sealing of the connectors makes it very difficult to re-enter the connector and can often cause damage to the connector during removal.